<?php
    
    $count = array(); // 计数器
    $disc  =  array('60','15','10','5');  //概率分布
    $i     =  1; //循环计数
    
    while($i)
    {
        $res  =  0;
        $pSum =  array_sum($disc);
        
        foreach($disc as $key=>$value)
        {
            $pNum = mt_rand(1, $pSum);
            
            if($pNum < $value)
            {
                $count[$key] += 1;
                break;
            }
            else
            {
                $pSum -= $value;
                continue;
            }            
        }
        
        if($i >= 10000)
        {
            break;
        }
        
        print $i++;
    }
    
    print_r($count);
